1. How do we know how life began?
Origin of Life
How do we know how life began?

2. Voyager’s Golden Record
The Voyager Golden Records are phonograph records which were included aboard both Voyager spacecraft, which were launched in They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them. The Voyager spacecraft are not heading toward any particular star, but Voyager 1 will be within 1.6 light-years of the star Gliese 445, currently in the constellation Camelopardalis, in about 40,000 years.[1]
As the probes are extremely small compared to the vastness of interstellar space, the probability of a space-faring civilization encountering them is very small, especially since the probes will eventually stop emitting electromagnetic radiation meant for communication.

3. Hypothesis 1: Life delivered through comets
Late heavy bombardment of comets 4 billion years ago
Panspermia: hypothesis that life on Earth originated from material delivered by a comet, either in the form of amino acids or as hardy bacteria
Living organisms “seeded” on earth as “passengers” aboard comets
Avoids the problem of life originating on earth, transfers problem of origin of life to another place
Asteroid: A relatively small, inactive body, composed of rock, carbon or metal, which is orbiting the Sun.  Comet: A relatively small, sometimes active object, which is composed of dirt and ices. Comets are characterised by dust and gas tails when in proximity to the Sun. Far from the Sun it is difficult to distinguish an asteroid from a comet.   Meteoroid: A small particle from an asteroid or comet orbiting the Sun

4. Hypothesis 2: Spontaneous formation
Age of earth: about 4.6 billion years ago
Conditions of pre-biotic earth
High temperature
High levels of carbon dioxide and other green house gases  produce globally high temperatures
Lightning
Reducing atmosphere (no O2)
Hydrogen and hydrogen-containing gases: methane, ammonia, hydrogen sulfide
Carbon dioxide, nitrogen, water vapor
Formed from volcanic activity

5. Hypothesis 2: Spontaneous formation
Simulate high energy sources
Electric spark (simulate lightning)
Heating water (simulate high temperature)
Simulate reducing atmosphere
Water vapor, hydrogen, methane, ammonia (HAM)
Products: mixture of amino acids
Amino acids = building blocks of life, what makes proteins

7. From amino acids to cells?

8. Cells research
(Click on interactive cell models)
Watch a video about cells